1. Field of the Invention
The present invention relates to a reciprocation-piston-type refrigerant compressor which is improved to increase its discharge and suction efficiency.
2. Description of the Related Art
In the field of compressors, a well-known reciprocating-piston-type refrigerant compressor comprises a cylinder block including a plurality of parallel cylinder bores arranged around an axial drive shaft, and double-headed pistons slidably provided within the cylinder bores for reciprocating between the top dead center and the bottom dead center. The refrigerant gas is compressed by the reciprocating double-headed pistons. A swash plate cooperating with the pistons is mounted on the drive shaft inserted into a center bore in the cylinder block. When the drive shaft rotates, the pistons are reciprocated within the cylinder bores, by the swash plate. An example is shown is Japanese Unexamined Patent Publication (Kokai) No 1-134085.
Front and rear housings, each of which includes a suction chamber and a discharge chamber, are sealingly attached to both ends of the cylinder block. Valve assemblies with valve plates and suction and discharge valves are provided between the cylinder block and the front and rear housings. The valve plates include suction ports which provide fluid communication between the suction chamber and the cylinder bores, and discharge ports which provide fluid communication between the discharge chamber and the cylinder bores. The suction valves and the discharge valves are provided at the suction ports and the discharge ports, respectively.
The refrigerant gas is introduced from the suction chamber into the cylinder bores within which the pistons move toward the bottom dead center through the suction valves, and the refrigerant gas in the cylinder bores within which the pistons move toward the top dead center is compressed and discharged through the discharge valves into the discharge chambers. The suction valves and discharge valves are opened by the differential pressure of the refrigerant gas passing therethrough.